Cognitive functions in prepsychotic patients

Objective: Cognitive dysfunctions are now widely understood as an essential feature of schizophrenia. A great number of cognitive disturbances have been described in drug-naive first-episode patients as well. The full-blown psychotic symptoms are usually preceded by a longer prodromal period, in which non-specific psychological disturbances are already present. The late prodromal phase is also coined as the prepsychotic state, with attenuated, isolated psychotic symptoms. The aim of the present study was to detect cognitive dysfunctions among young adults at the prepsychotic stage with the use of a standardized computer based cognitive test battery. Method: Eleven (9 men, 2 women) young Hungarian adults referred to the Outpatient Clinic of the Department of Psychiatry at the University of Debrecen were studied. The patients were re-evaluated for psychotic symptoms after 12 months. The patients had no history of psychiatric disorders or psychotic episodes and were referred by general practitioners on account of non-specific emotional or behavioural abnormalities. The subjects were asked to perform a series of 13 computerized neuropsychological tests of the Cambridge Neuropsychological Test. The performance of the patients were compared to that of the standardized database of the Cambridge Neuropsychological Test. Results and discussion: The performance of the prepsychotic patients was significantly lower compared to the healthy individuals in the paired associate learning (PAL, p<0.001), Spatial recognition memory (SRM, p<0.05), Rapid visual processing (RVP, p<0.05), and Spatial working memory (SWM, p<0.05) tests. Conclusion: Cognitive deficits were found mainly in attentional, frontal and preftontal cognitive functions. These impairments may be present at the early stages of the development of psychosis and the standardized cognitive test battery (CANTAB) might be a useful tool for the detection of early cognitive impairments and provide a rationale for early intervention in individuals at risk of developing psychosis. (c) 2005 Elsevier Inc. All rights reserved.